In 1959, the successor of the IMS 57 was launched, with numerous changes and improvements introduced as the Campulung factory developed along with its products. Victor Nagy, the director of the factory, employed specialists such as Gheorghe Zotta, a very experienced aeronautical engineer, Octvian Waschievici, a technician who would later design the famous M461, and Aurica Niculescu and Gheorghe Potinchiu, the latter of whom would become a highly respected professor of engineering. Together, they were occupied not only with modernising the IMS 57, but also with coordinating the factory’s modernisation and development.

The first changes were to the bodywork: it was shorter by 150 mm and was entirely produced at Campulung. The chassis was shortened by 100 mm; it is easily distinguished from that of the later M461 through the “window” of the rear cardan joint, which is oval. The new model was named after the region of prodcution, Muscel (M) and the launch year, 1959. The bodywork was made more rigid by using pressed elements from the Steagul Rosu (Red Flag) factory at Brasov, reducing the mass by 70 kg.

The first models produced kept the rear axle, engine and gearbox from IMS 57. The engine’s power was increased to 56 hp by redesigning the ventilating chambers and using the Romanian-designed carburettor, UT 550 (vertically placed, with a descending circuit, one mixing chamber, a double diffuser, a mechanic accelerator and an acceleration pump. M 59 was bodied at Campulung, and the “Vasile Tudor” plant at Colibasi, which would become the Dacia plant, was used to manufacture parts made from cast iron and non-ferrous metals, especially those in the gearbox.

Meanwhile, the factory’s specialists had found the solution to giving the car a more modern engine. Uzina de Autcamioane Brasov (Brasov Truck Factory) was producing a V8 engine derived from the Ford V8 produced before the war in Bucharest, in what is now the Automatica works. An engine was designed which used the components of the V8; it was nicknamed the “semi-Carpati” after the truck being produced in Braşov. The new engine and accompanying four-speed gearbox represented an important step forward. The Ministry of Defence was particularly pleased and completely stopped importing the GAZ 69, in favour of the indigenous model.

Compared to the IMS 57, the bodywork of the M 59 was completely redrawn, although still inspired by that of the GAZ. It has several distinguishing features: the windscreen is still two-piece but with electric wipers at the top; the petrol filler cap is on the rear left wing; the spare wheel is fixed in the middle of the bodywork, because of which the left door is shorter than the right one; the door hinges are made of cast iron; the system supporting the lowering of the windscreen uses two hinges and two supports on the bonnet; the accumulator’s box is on the left side underneath the driver’s seat; the storage compartments in the inner rear wings are accessed from the inside; the indicators are round; on models with the M207 engine the grille has another hole for a handle (the new engine was a little unbalanced when compared to its predecessor). It must be stressed that body parts are not interchangeable between an M 59 and a GAZ 69. The production of M 59 grew impressively, from 803 units in 1959 to 3222 in 1963. M 59 was manufactured until 1964 when it was replaced by a new model, M 461.